The plant hormone jasmonic acid (JA) has a crucial role in both host immunity and development in plants. Here, we report the importance of JA signaling in the defense system of rice. Exogenous application of JA conferred resistance to bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo) in rice. Expression of OsJAZ8, a rice jasmonate ZIM-domain protein, was highly up-regulated by JA. OsJAZ8 interacted with a putative OsCOI1, which is a component of the SCF(COI1) E3 ubiquitin ligase complex, in a coronatine-dependent manner. OsJAZ8 also formed heterodimers with other OsJAZ proteins but did not form homodimer. JA treatment caused OsJAZ8 degradation and this degradation was dependent on the 26S proteasome pathway. Furthermore, the JA-dependent OsJAZ8 degradation was mediated by the Jas domain. Transgenic rice plants overexpressing OsJAZ8ΔC, which lacks the Jas domain, exhibited a JA-insensitive phenotype. A large-scale analysis using a rice DNA microarray revealed that overexpression of OsJAZ8ΔC altered the expression of JA-responsive genes, including defense-related genes, in rice. Furthermore, OsJAZ8ΔC negatively regulated the JA-induced resistance to Xoo in rice. On the basis of these data, we conclude that JA plays an important role in resistance to Xoo, and OsJAZ8 acts as a repressor of JA signaling in rice.

Jasmonic acid (JA) and salicylic acid (SA) play important roles in plant defense systems. JA and SA signaling pathways interact antagonistically in dicotyledonous plants, but, the status of crosstalk between JA and SA signaling is unknown in monocots. Our rice microarray analysis showed that more than half of the genes upregulated by the SA analog BTH are also upregulated by JA, suggesting that a major portion of the SA-upregulated genes are regulated by JA-dependent signaling in rice. A common defense system that is activated by both JA and SA is thus proposed which plays an important role in pathogen defense responses in rice.

Key Points• S100A91 neutrophils accumulated prominently in the central area of granulomas in humans and guinea pigs.• Granuloma formation was markedly impaired by a treatment with the S100A9 inhibitor, tasquinimod. antigen as S100A9, a calcium-binding protein of the S100 family, which was expressed abundantly in neutrophils. Consistent with the multifaceted functions attributed to S100A9, including its role in neutrophil extravasation and macrophage activation, the blockade of S100A9 functions with the specific inhibitor, tasquinimod, impaired the formation of organized granulomas with neutrophil cores. These results demonstrate the critical role of neutrophils and the S100A9 protein in granuloma formation. Because intragranuloma S100A9 1 neutrophils were also detected in humans, these results indicate the potential of tasquinimod, a new anticancer drug candidate, for manipulating human granulomatous diseases.

PurposeWe aimed to compare the preventive effect of 5-day administration of aprepitant with single administration of fosaprepitant meglumine against nausea and vomiting symptoms due to highly emetogenic chemotherapy regimens comprising cisplatin (CDDP).MethodsSubjects were inpatients who underwent chemotherapy for gastric cancer, esophageal cancer, lung cancer, or head and neck cancer with a regimen comprising 60 mg/m2 or higher dose of CDDP. In this randomised, open-label, controlled study, the subjects were assigned to a group given aprepitant for 5 days or a group given a single administration of fosaprepitant meglumine. The nausea and vomiting symptoms that emerged within 7 days after the first CDDP administration were investigated with a questionnaire form; the results were compared between the two groups. Risk factors affecting nausea and vomiting symptoms were also investigated.ResultsOf the 101 patients enrolled, 93 patients were included (48 in the 5-day aprepitant group and 45 in the single fosaprepitant meglumine group). No significant intergroup differences in the complete response rate or the complete control rate were found over the entire period. The nausea score tended to increase from day 3 in both groups, but no significant intergroup difference was observed. Furthermore, the investigation of risk factors affecting moderate or severe nausea symptoms indicated that the fosaprepitant meglumine administration was not a risk factor.ConclusionsSingle administration of fosaprepitant meglumine was not inferior to 5-day administration of aprepitant for preventing acute and delayed nausea and vomiting symptoms occurring after administration of CDDP (60 mg/m2 or higher).